[sDIY] CV output buffer chip?

[harry bissell]

Toby: Fair warning... Most op-amps that can approach the negative rail have
very limited current sinking capacity... they can tolerate only a very light
load. This isn't too bad if the input to the next stage is also ground
referenced, but if it isn't watch out. The CMOS op amp is the CA3130. The
CA3140 has a bipolar output. Which one will swing lower is a function of the
load you have....

Why not try a Charge pump to make a negative 5 volt supply and sleep easy at
night. (Maxim MAX660 or similar). Then you can have your cake and include
decent performance at ground too...   :^) Harry

Paul Maddox wrote:

> Toby,
>
> Try the CA3140, or one of its brothers 3240 (I think is a dual)
>
> >I'm finding that I have the op-amp skills of a breadstick.
>
> we all started somewhere.. get a book, "how to use opamps" by Penfold from
> Babani press, great book... gives you all the useful formulas, circuit
> diagrams and configurations..
>
> >It seems that the combination of single 5v supply and
> >output going nearly to rails is the killer.
> >
>
> yep, this is *VERY* limiting... if you only had a dual rail PSU with +12v
> and -12v, life would be easier, but hey it would also be boring!
>
> >  - -- -  Toby Paddock
> >http://www.seanet.com/~tpaddock
> >
>
> Paul
>
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